Good question, I have the same request/task. Meanwhile dealing with R80.30, though.
In my case there are being maintained two groups (case 1) and another three groups (case 2) in parallel by accident or on purpose...I don't know. They grew appart to some degree over the months. Fullfilling different purposes. Both cases are independent from each other and to be seen as seperate cases.
I have the been given the task in each of the cases to merge the group of two (one has about 40 the other about 100 entries) into one and the group of three groups (similarly large) into another single group. In both cases one of the involved groups could be the destination group of the other(s).
It would be nice to not have to comapre and copy & paste one groups content manualy into the other. An automatic way of doing this while also taking care of IP-duplicates would be a life time saver!
Has there been a solution to this already?
Best regards
Carsten